Fix double-escaping of non-highlighted code blocks in Astro-flavored markdown (#4169)

Author: hippotastic

.changeset/strong-hotels-cross.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/markdown-remark': patch
+---
+
+Fix double-escaping of non-highlighted code blocks in Astro-flavored markdown

packages/markdown/remark/src/rehype-escape.ts

@@ -1,4 +1,4 @@
-import { visit } from 'unist-util-visit';
+import { visit, SKIP } from 'unist-util-visit';
 
 export function escapeEntities(value: string): string {
 	return value.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
@@ -14,8 +14,9 @@ export default function rehypeEscape(): any {
 				visit(el, 'raw', (raw) => {
 					raw.value = escapeEntities(raw.value);
 				});
+				// Do not visit children to prevent double escaping
+				return SKIP;
 			}
-			return el;
 		});
 	};
 }

packages/markdown/remark/test/entities.test.js

@@ -2,11 +2,25 @@ import { renderMarkdown } from '../dist/index.js';
 import { expect } from 'chai';
 
 describe('entities', () => {
-	const renderAstroMd = (text) => renderMarkdown(text, { isAstroFlavoredMd: false });
-
-	it('should not unescape entities', async () => {
-		const { code } = await renderAstroMd(`<i>This should NOT be italic</i>`);
+	it('should not unescape entities in regular Markdown', async () => {
+		const { code } = await renderMarkdown(`<i>This should NOT be italic</i>`, {
+			isAstroFlavoredMd: false,
+		});
 
 		expect(code).to.equal(`<p>&#x3C;i>This should NOT be italic&#x3C;/i></p>`);
 	});
+
+	it('should not escape entities in code blocks twice in Astro-flavored markdown', async () => {
+		const { code } = await renderMarkdown(
+			`\`\`\`astro\n<h1>{x && x.name || ''}!</h1>\n\`\`\``,
+			{
+				isAstroFlavoredMd: true,
+				syntaxHighlight: false,
+			}
+		);
+
+		expect(code).to.equal(
+			`<pre is:raw><code class="language-astro">&lt;h1&gt;{x &amp;&amp; x.name || ''}!&lt;/h1&gt;\n</code></pre>`
+		);
+	});
 });